1. Field of the Invention
The present invention relates to an image forming apparatus, such as a color copying machine and a printer, which forms an image on a recording sheet by an electrophotographic printing method, and a control method therefor.
2. Description of the Related Art
Conventionally, in an image forming apparatus, such as a copying machine, a facsimile machine, and a printer, toners or developing materials are filled in respective cartridges (replaceable units) removable from the apparatus body, and these cartridges are mounted on the image forming apparatus, whereby the toners or developing materials are supplied to the image forming apparatus. Then, when any of the toners or developing materials in the cartridges runs out, the corresponding cartridge is replaced by a new one, whereby the tone or developing material is replenished.
Recently, as a means for detecting replacement of the existing cartridge by a new one or a depletion of a toner or developing material, there has been proposed a cartridge with a memory tag (memory device). By causing cartridge identification information, life information, image processing information, etc. to be stored on the memory tag, it is possible to grasp the latest state of the cartridge and perform the optimum image formation (see e.g. Japanese Laid-Open Patent Publications No. 2004-093693 and No. 2005-107113).
However, in the conventional technique, if a memory tag is faulty due to some cause, it is impossible to perform a failsafe image forming operation. Therefore, the user is required to procure a cartridge again, which can cause a marked degradation of working efficiency.